Let it go and move forward

Quick request for advice.

Last september I had a devastating blow when my career path was stopped in my last year of training. Since then I have been unable to fully move on and I am still unable to let it go. I think about was has happened everyday fixating on it and replaying it and the causes.

It is making me unwell with growing low self esteem and my ability to cope with it is getting more difficult. I struggle to process the pain that comes with replaying it and this manifests in physically unhealthy ways.

What I am asking for is any ways that have helped others to let go of unhealthy fixations.

Any formulas for letting go of things that are painful and moving forward?

Thank you